Metformin Double Duty: Diabetes and Prostate Cancer

Research finds diabetic men with prostate cancer lived longer on metformin, reports David B. Samadi, MD, top robotic prostate surgeon

New York, New York, UNITED STATES

New York, NY, Aug. 27, 2013 (GLOBE NEWSWIRE) -- Researchers in Canada share promising news for men with type 2 diabetes and prostate cancer. Long-term use of metformin for blood sugar control may also reduce the risk of prostate cancer death. For every six months of cumulative metformin treatment after prostate cancer diagnosis, risk of death dropped 24 percent. Sold under the brand names Glucophage, Glumetza, Riomet, and Fortamet, metformin is commonly prescribed to those with type 2 diabetes, sometimes in conjunction with insulin.

Dr. David Samadi, Chairman of Urology, Chief of Robotic Surgery at Lenox Hill Hospital and Professor of Urology at Hofstra North Shore-LIJ School of Medicine, believes these crossover findings could be very meaningful given the prevalence of both diseases, particularly in older men. However, more research is needed before metformin is added to the list of prostate cancer treatments, which includes robotic prostate surgery and radiation for prostate cancer.

The metformin results are based on a review of the medical records of Canadian men with both diabetes and prostate cancer. In observation of nearly 4,000 men, all age 67 or older, a strong link was discovered between long-term use of metformin and a lower risk of prostate cancer death. Interestingly, all-cause mortality also declined after six months of metformin treatment.

Findings appear in the Journal of Clinical Oncology, August 5,

"The compounding impact of metformin on prostate cancer-specific mortality appears significant," said Dr. Samadi. "When a drug has a long track record of success with one disease, it's in our best interest to explore how it might benefit those with other conditions, as well. As we learn more, we may see metformin as a future adjunct therapy for prostate cancer."

As an affordable, safe, and well-tolerated medication, metformin is widely used and regarded in the treatment of type 2 diabetes. The long-term dose-response association with prostate cancer was only seen among the one-third of men taking a standard metformin dosage, not the remaining two-thirds using other forms of diabetes treatment.

While the findings do not indicate that metformin use prevents prostate cancer in any way, they do provide a promising foundation for further exploration. Researchers intend to study the use of metformin in prostate cancer patients, independent of type 2 diabetes, using large-scale, randomized trials.

For now, researchers concluded that metformin should continue to be used as a first-line type-2 diabetes treatment, particularly in men who also have prostate cancer.

Dr. David Samadi leads a diverse team of prostate cancer experts at the Lenox Hill Hospital Prostate Cancer Center in New York.

A photo accompanying this release is available at:

David B. Samadi, MD